Devices for cold-rolling and planishing metal sheet



Feb. 18, 1969 P. GAY 3,427,848

DEVICES FOR COLD-ROLLING AND PLANISHING METAL SHEET Filed June 20, 1966 Sheet of 2 Feb. 18, 1969 P. GAY 3,427,848

DEVICES FOR COLD-ROLLING AND PLANISHING METAL SHEET Filed June 20, 1966 Sheet 2 of 2 United States Patent 3,427,848 DEVICES FOR COLD-ROLLING AND PLANISHING METAL SHEET Pierre Gay, St. Etienne, Loire, France, assignor to Compagnie des Ateliers et Forges de la Loire (St. Chamond,

Firminy, St. Etienne, Jacob-Holtzer), Paris, France Filed June 20, 1966, Ser. No. 558,634 Claims priority, applicgtitig France, Aug. 23, 1965, 9 4

US. Cl. 72-205 Int. Cl. B21b 39/08, U28

, 6 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a device for cold-rolling a metal sheet to the desired degree.

The necessity of subjecting a metal sheet to a rolling operation in order to impart a certain rate of cold-hardening thereto is widely acknowledged. This operation, also called skin-pass, is carried out in a rolling stand disposed between an unroller and a take-up drum capable of imparting certain tension values to the sheet before and after the rolling cylinders.

It is also known that the metal sheet must be subjected to a planishing or leveling operation.

It is the object of the present invention to provide a device for imparting a predetermined degree of coldhardening to a metal sheet by subjecting same to a rolling operation followed by a planishing or leveling operation whereby the elongation resulting in the metal sheet as a consequence of these two successive operations, and therefore the degree of cold-hardening, have predetermined or the desired values.

According to this invention, the sheet is caused to pass firstly through a rolling stand and then through a planishing or leveling stand, the sheet speeds at the inlet end of the rolling stand and at the outlet end of the planishing or leveling stand having a predetermined adjustable ratio.

This device comprises a rolling stand and a planishing or leveling stand disposed between two cylinder units termed the one the driving unit and the other the retaining unit, each cylinder unit consisting of a pluraliy of cylinders over and under which the sheet is caused to pass alternately, adequate coupling means being provided for keeping the peripheral speeds of the cylinders of said retaining unit and of the cylinders of said driving unit at a predetermined adjustable ratio.

Other features and advantages of this invention will appear as the following description proceeds with reference to the attached drawing illustrating diagrammatically by way of example a typical form of embodiment of the invention. In the drawings:

FIGURE 1 is an elevational, very diagrammatic view, showing the principle of the device of this invention;

FIGURE 2 is an elevational view showing a typical form of embodiment of the device of this invention; and

FIGURE 3 is a plan view of the arrangement shown in FIGURE 2.

Before giving a complete description of the device constituting the subject-matter of this invention a brief description of the basic principles of the method of the invention will first be given.

Referring first to FIGURE 1, this figure illustrates the essential component elements of a device for carrying out this method.

The sheet 1 to be cold-hardened by rolling is fed in the direction of the arrow. This sheet 1 is rolled in a coldrolling stand comprising working cylinders 2 and 2.

Upon completion of this cold-rollling operation, the sheet is directed through a planishing or leveling unit designated as a whole by the reference numeral 3 in the figure and wherein the sheet is flexed alternately in one and the other direction.

According to this invention a device for continuously tensioning the sheet 1 is associated with the rolling stand and the planishing or leveling unit, whereby if A is a point of sheet 1 which is located upstream of the rolling stand, and if this point A travels at a speed VA, and if B is a point of said sheet 1 which is located after the planishing unit, and if this point B travels at a speed VB, a predetermined or desired speed ratio VB/ VA can be imposed at will.

The following results are derived from this combination of means inherent to the present invention (rolling stand, planishing or leveling unit and sheet-elongating device):

Firstly, the rolling and planishing steps can be performed in a single and same operation, which is particularly advantageous; thus, the elongation resulting from these two successive steps and therefore the degree of coldhardening of the end product will have the desired value.

This result would not be obtained if tractive efforts were applied to the sheet at points A and B.

In fact, variable elongations and therefore variable degrees of cold-hardening are obtained according to the magnitude of the pressure exerted by the rolling cylinders, the relative imbrication of the rolls of the planishing cylinders, the sheet width and thickness, and the nature of the metal constituting the sheet.

This last remark sets in sharp contrast the difficulty to be expected in the operation of a machine in which predetermined mechanical tensions would be imposed. In fact, in case of variation in one of the above-mentioned parameters, in addition to unavoidable variations in the degree of cold-rolling, sheet ruptures are most likely to take place if the adjustment is not properly done. Now this risk is precluded if the sheet elongation is properly controlled.

In the following disclosure it will also be seen that the device according to this invention can be used with either the planishing unit or the rolling stand inoperative, this possibility constituting an interesting feature if only one of the planishing or rolling operations on the sheet is contemplated.

Referring now to FIGURE 2, the metal sheet 1 travelling in the direction of the arrow F enters a retaining unit designated generally by the reference numeral 22. In the specific form of embodiment illustrated] in the figure, this unit 22 comprises five cylinders such as 24 having their axes of rotation parallel to each other; the sheet 1 is caused to pass alternately over and under these cylinders, as shown.

,A presser roller 23 parallel to said cylinders 24 applies the metal sheet 1 as it enters the retaining unit against the first cylinder 24 of the unit, so that the device may operate with a slackened sheet upstream of unit 22 (at point A of FIGURE 1). The presser roller 23 has its end trunnions journaled in a pair of parallel levers 26, 26' fulcrumed on a fixed shaft 27 carried by the unit 22 and parallel to the aforesaid cylinders 24. These levers 3 26, 26' are each responsive to a piston-cylinder unit such as 28 (FIGURE 2) having its cylinder attached t the frame structure of the retaining unit 22 by means of a member 29, the piston being attached to the end of the corresponding lever 26 or 26' which is opposite to said presser roller 23.

As it emerges from the retaining or input unit 22, the sheet 1 enters a rolling stand 4 comprising two coldrolling cylinders 30 and 31, and inlet and outlet guide rollers 32 and 33 respectively.

When delivered from the rolling stand 4 the metal sheet 1 is fed to a planishing or leveling machine designated by the general reference numeral 5. This machine operates by alternate transverse flexing and is equipped with an anti-rib stand as depicted in the British Patent 1,028,537 and in the US. Patent No. 3,326,026.

This planishing or levelling machine comprises rolls 34 and 35 producing a sheet distorsion by alternate flexures, each roll being provided with two bearing rollers designated by the reference numerals 36, 36 and 37, 37' respectively for preventing the rolls 34 and 35 from sagging. The bearing rollers 36 and 36 are mounted on a plate 38, and the bearing rollers 37 and 37 are mounted likewise on a plate 39.

The planishing or levelling machine 5 further comprises an anti-tilting device according to the aforesaid British patent and U.S. patent, which comprises a cylinder 40 trunnioned in bearings provided in a plate 43 solid with plate 39. This cylinder presses the metal sheet 1 against a small roller 41 called tile-correcting roll supported by a pair of bearing rollers 42, 42 to prevent same from sagging. As described in the aforesaid British patent and US. patent the vertical position of the tile-correcting roll 41 is adjustable to remove the tile effect. To this end, the roller 41 and its bearing rollers 42 and 42 are mounted on a common support 44 adapted to pivot about a shaft 45 under the control of an eccentric system comprising a disc 47 adapted to rotate about a shaft 46 eccentric in relation to the disc center.

As it emerges from the planishing or leveling machine 5 the sheet is carried along by a driving or outlet unit designated as a Whole by the reference numeral 6. In the specific form of embodiment illustrated this unit 6 comprises five cylinders such as 25 having their axes parallel to those of cylinders 24, the sheet 1 being alternately flexed by passing over and under these cylinders, as shown.

As in the case of the input unit, a presser roller 7 is provided for pressing the sheet against the last cylinder 25 of unit 6 so that the device can operate with a slackened sheet at the outlet end of this unit 6 (point B of FIGURE 1). This presser roller 7 is mounted like the presser roller 23; in other words, it is trunnioned in the ends of a pair of levers such as 48 fulcrumed on a pivot pin or shaft 49 rigid with the frame structure of unit 6. These levers are responsive to piston and cylinder actuators connected in 51 to the ends of levers 48 which are opposite to said roller 7. As this device is identical with the one described hereinabove in connection with roller 23, it is not shown in FIGURE 3.

The mechanism for driving the various parts of the device of this invention will now be described with reference to FIGURE 3.

This mechanism is driven from a motor 17 having two shaft ends 52 and 53. The shaft end 52 is coupled to the device designated as a whole by the reference numeral 14 and termed hereinafter connecting box.

This connecting box, of which the functions will be set forth in detail presently, comprises conventional means such as gearings, a differential and clutches.

The following shafts emerge from this connecting box and are rotatably driven from the output shaft 52 of motor 17 through said box 14:

(1) Shaft (or shafts) driving the extension (or extensions) 54 through which the cylinders and 31 of the cold-rolling stand 4 are rotatably driven; any one or both of said cold-rolling cylinders 30, 31 may be driven, so that the arangement will include one or two shafts 20 and one or two extensions 54.

(2) Shaft 12 driving the retaining or input unit 22 through a distributor box 11. This shaft 12 drives the distributor box through the medium of a friction coupling 55 acting as a torque limiter.

(3) Shaft 9 driving the distributor box 8 of the output tensioning or driving unit 6.

(4) Shaft 56 through the medium of the differential 15.

Under these conditions it will be seen that:

The retaining unit 22 comprising the cylinders 24 is driven through the distributor box 11 actuated by the power shaft 12. This distributor box is a simple gearbox designed for simultaneously starting the output shafts 58 at the same rotational speed. The output shafts 58 drive in turn the shafts 13 of cylinders 24 through the medium of a reduction gearing designated as a whole by the reference numeral 59.

Alternately, a magnetic power clutch of the type disclosed in the British patent application No. 27,064/64 and US. Patent No. 3,362,202 to Gay may be interposed on shafts 58, between the box 11 and reduction gearing 59.

Similarly, the output or driving unit 6 i driven from shaft 9 (and therefore from motor 17) through the aforesaid distributor box 8. The design of this distributor box 8 is similar to that of distributor box 11 and consists therefore of a gearbox for rotatably driving the output shafts 60 from the input shaft 9. These output shafts 60 drive in turn the shafts 10 of cylinders 25 through a suitable reduction gearing 62 and possibly clutches 61 similar to the aforesaid clutches 57.

The connecting box 14 consisting of conventional means (pinions, differential 15 and clutch) provides the following functions:

(i) In one position of its clutch (not visible in the drawing because in the box) the shaft 52 is mechanically coupled to shaft (or shafts) 20.

Simultaneously, shaft 9 is connected through differential 15 to shaft 12. This differential 15 is so designed that the velocity of rotation of shaft 12, that is, ca has the following characteristic:

m is the velocity of rotation of shaft 9.

01 181116 velocity of rotation of shaft 56.

K and K being constants depending on the number of teeth of the various pinions of the trains of gears in connecting box 14. As a rule, K 1.

(ii) In another position of said clutch of connecting box 14, shaft 20 is not driven and can rotate freely, shaft 52 is mechanically connected to shafts 12 and 9. Thus, again Drivingly connected to the end of shaft 53 of motor 17 is a hydraulic, variable-output pump 18. This pump is adapted to supply fluid under pressure to a hydraulic motor 16 controlling through a reduction gearing 21 the rotation of shaft 56. According to a modified form of embodiment of this invention, a variable-speed gearing may be used for rotatably driving the shaft 56 from shaft 53.

It will be noted that if the hydraulic motor 16 is stopped both shafts 9 and 12 revolve at the same speed K =1 and, if this hydraulic motor is operated, the speed of shaft 12 differs from that of shaft 9 (thus elongating the sheet 1). By properly adjusting the variable-output pump 18 feeding the hydraulic motor 16, the desired ratio is obtained between the speeds of shafts 12 and 9 (thus positively controlling the value of the sheet elongation), and moreover the velocity of rotation of shaft 56 (i.e. @1 is proportional to the rotational speed of output shaft 52 of motor 17 and therefore to the linear speed of the sheet to be treated.

In order to hold the device against motion when desired, a brake 63 is provided.

Now reference Will be made to FIGURES 2 and 3 of the attached drawings to describe the mode of operation of the device illustrated therein.

If the cold-rolling stand 4 is used, the clutch of the aforesaid connecting box 14 is released and sheet 1 is driven by the cold-rolling cylinders 30, 31 of stand 4 which constitute in this case the driving medium of the assembly.

The speed ratio of cylinders 24 and 25 respectively of retaining unit 22 and output unit 6 is obtained through the driving connections provided by the above-described mechanisms 8, 11, 14, 15 and 16, 18.

Under these conditions, it is clear that the sheet elongation is given a predetermined adjustable value.

It Will be seen that with the device of the present invention it is possible to leave in their inoperative condition: either the planishing or leveling machine 5, or the cold-rolling stand 4, by engaging the clutch of connecting box 14, whereby the planishing operation and/ or the cold-rolling operation can be performed on the sheet 1.

Furthermore, the clutch of connecting box 14 may be replaced, if desired, by a sliding dog clutch. In one position this sliding dog clutch will drive the shaft or shafts driving the cold-rolling cylinders, and in the other position it will drive the pinions of connecting box 14.

With the combination of means according to the device of this invention it is possible to perform simultaneously the cold-rolling and leveling operations, so that the elongation resulting from these two successive mechanical treatments, and therefore the cold-hardening of the end product, will have the desired value.

Of course, this invention should not be construed as being limited by the specific form of embodiment shown and described herein by Way of example, since it includes all the possible variations and modifications thereto.

In case the specific application contemplated for metal sheets requires a spotless surface condition, notably the obtaining of metal sheets free of any scores or scratches, even extremely fine ones, it will be advantageous to provide a driving device for properly distributing the driving and reaction torques among the cylinders of each driving and retaining units to avoid any undesired slipping of the sheet on the cylinders. This device is constituted by a magnetic powder clutch 57 to 61 driving the cylinders 24, 25 respectively of each unit 22 and 6. These magnetic powder clutches are disclosed in the British patent application No. 27,064/ 64 and U.S. Patent No. 3,361,155 by same applicant.

What is claimed is:

1. A device for cold-hardening sheet metal stock, comprising a cold-rolling stand, a leveling stand disposed in succession to said cold-ro1ling stand in the direction of feed of the sheet to be processed, a sheet driving unit disposed at the outlet end of said leveling stand, a sheet retaining unit disposed at the inlet end of said cold-rolling stand, and means for adjustably setting the ratio of the linear speed of said sheet at the inlet end of said coldrolling stand to the linear speed of said sheet at the outlet end of said leveling stand at a predetermined, adjustable value, whereby the sheet elongation produced between said inlet and outlet ends, and therefore the cold-hardening of said sheet, may be given a predetermined value.

2. A device as set forth in claim 1, wherein each one of said sheet retaining and driving units consist of a train of cylinders, said sheet being alternately passed over and under the successive cylinders of each unit.

3. A device as set forth in claim 1, wherein each one of said sheet retaining and driving units consists of a train of cylinders, said sheet being passed alternately over and under the successive cylinders of the unit, a presser roller at the inlet end of said retaining unit which is adapted to press the sheet being processed against the first cylinder of the relevant :unit, and another presser roller at the outlet end of said driving unit which is adapted to press the processed sheet against the last cylinder of said driving unit, for feeding said sheet in an unstressed con dition to said device and delivering said sheet in an unstressed condition from said device.

4. A device for cold-hardening sheet metal stock, comprising a cold-rolling stand and a leveling stand disposed in succession in the direction of feed of the sheet to be processed, a sheet driving unit disposed at the outlet end of said leveling stand, a sheet retaining unit disposed at the inlet end of said cold-rolling stand, each one of said sheet retaining and driving units consisting of a train of cylinders, said sheets being alternately passed over and under the successive cylinders of each unit, a presser roller at the inlet end of said retaining unit which is adapted to press the sheet being processed against the first cylinder of the relevant unit, and another presser roller at the outlet end of said driving unit which is adapted to press the processed sheet against the last cylinder of said driving unit for feeding said sheet in an :unstressed condition to said device and delivering said sheet in an unstressed condition from said device, a differential mechanism for driving said retaining and driving units, hydraulic power means releasably connected to said differential mechanism and adapted, when operative, to impart to said driving unit a speed differing from the speed of said retaining unit.

5. A device as set forth in claim 4, comprising an electric motor, a hydraulic pump driven from said electric motor and adapted to supply fluid under pressure to said hydraulic motor, a mechanism also driven from said electric motor, and clutch means associated with said mechanism for transmitting the motion either to all the working cylinders of the device or to a single working cylinder thereof, and/or to the cylinders of said driving and retaining units.

6. A device as set forth in claim 5, wherein means are provided for automatically adjusting the torque applied to the cylinders of said driving and retaining units for delivering from the device a sheet with a spotless, scratchfree surface.

References Cited UNITED STATES PATENTS 2,030,817 2/1936 'Fenton 29-17 2,189,329 2/ 1940 Sendzirnir 72205 2,214,618 9/ 1940 Kenyon et al 72-205 X 2,742,949 4/ 1956 Nilsson 72-205 FOREIGN PATENTS 1,372,010 8/ 1964 France.

MILTON S. MEHR, Primary Examiner.

U.S. C1. X.-R. 72-161 

